Golf club strikeface with off-axis directional grain structure

ABSTRACT

The golf club head described herein has a metal alloy strikeface formed from a faceplate having an off-axis directional grain structure. The directional grain structure can be formed of elongated grains. The faceplate can have a horizontal reference axis, extending in a heel to toe direction. The elongated grains can be angled in a longitudinal direction that is offset from the horizontal reference axis by an angle of between 5 and 85 degrees. The directional grain structure can be oriented from a low-heel region to a high-toe region of the strikeface. In some embodiments, the golf club head can have a relatively uniform characteristic time (CT) across the strikeface. Specifically, a CT differential across the strikeface can be between 0 and 7 μs.

FIELD

The present disclosure relates generally to golf equipment, and more particularly, to a golf club head having an anisotropic faceplate with an off-axis grain structure angled from low-toe to high-heel.

BACKGROUND

The flexibility of a strikeface (colloquially known as how “hot” the face is) correlates to the speed imparted to a golf ball upon impact. There are two methods for measuring the flexibility of a strikeface: characteristic time (CT) and coefficient of restitution (COR). Characteristic time (CT) is the amount of time, measured in microseconds, that the strikeface of the club head remains in contact with a metal ball used in a testing apparatus. CT measures the spring-like reaction of the strikeface. Coefficient of restitution (COR) is the ratio of final relative velocity to initial relative velocity between two objects after they collide. In golf, COR is tested by firing a golf ball at a stationary faceplate or club head strikeface. COR is measured as the ratio of the final relative velocity of the golf ball after collision/impact with the club head strikeface to the initial relative velocity of the golf ball prior to collision/impact. The COR indicates how much energy is transferred from the golf club to the golf ball at impact. In other words, COR shows the efficiency of the golf club head. Both CT and COR relate to the strikeface material properties, such as the modulus of elasticity.

The spring effect and dynamic properties of club heads with loft angles of 35 degrees or less is governed by the Equipment Rules Part 2, Section 4c, as administered by the R&A Rules, Ltd. (The R&A) and the United States Golf Association (USGA). Measurement of characteristic time (CT) is employed by the R&A and the USGA to determine conformance of a club head to the equipment rules. The characteristic time (CT) test was developed as a simpler method of testing the flexibility of a strikeface, compared to the more realistic but more time-intensive and equipment-intensive coefficient of restitution (COR) test.

To be conforming to the CT requirement, a golf club head (which includes the club face) must not have the effect of a spring which exceeds the limit set forth in the Pendulum Test Protocol (also called the Protocol for Measuring the Flexibility of a Golf Clubhead) on file with the R&A and the USGA (TPX3004 Rev. 2.0, Apr. 9, 2019) (available at https://www.usga.org/content/dam/usga/pdf/2019/equipment-standards/TPX3004%20Protocol%20for%20Measuring%20the%20Flexibility%20of%20a%20Golf%20Clubhead.pdf). In particular, for most wood-type golf club heads, a club head will be non-conforming if the CT value at the center of the face is greater than 239 microseconds (μs), plus an 18 μs tolerance. Furthermore, the club head will be non-conforming if the CT value exceeds 239 μs plus an 18 μs tolerance anywhere within the impact area, or exceeds 257 μs plus an 18 μs tolerance outside the impact area.

Due to the high strength and high flexibility of the metal materials used to make faceplates in current golf club heads, some equipment manufacturers are producing club heads that achieve close to the maximum CT limit. As described above, a club head having a CT above 239 μs (+/−18 μs) in any region within the impact area will be non-conforming. Therefore, if a region of the strikeface away from the geometric center has a higher CT value than the geometric center, the strikeface will be non-conforming while also failing to provide the maximum spring like rebound for the golf ball at the strikeface geometric center. The herein described strikeface design comprises a more uniform CT that not only conforms to the R&A and USGA regulations, but also provides golfers with a uniform and maximum efficiency response across the face.

Traditionally, the CT of a strikeface or faceplate was altered by changing the overall thickness of the faceplate. An overall thicker faceplate bends less, resulting in a lower CT. An overall thinner faceplate bends more, resulting in a higher CT. The anisotropic faceplate described herein lowers the CT value of the high-toe region without thickening the strikeface. In addition to correlating to the thickness of the strikeface, the CT value also correlates to the modulus of elasticity of the strikeface material. The CT value of the strikeface increases as the modulus of elasticity of the strikeface is decreased. Similarly, the CT value decreases as the modulus of elasticity is increased. The club head described herein employs a strikeface with an off-axis directional grain structure, which achieves a lower modulus of elasticity than similar strikefaces lacking the off-axis directional grain structure. This lower overall modulus of elasticity reduces the CT value of the high-toe region of the strikeface without necessitating an increase in the overall thickness of the strikeface.

Due to the mechanics of a golf swing, a majority of hits happen within the high-toe region of the strikeface. The prior art touts that aligning a faceplate's longitudinal grain structure (roll direction) in a high-toe to low-heel (HTLH) direction allegedly increases the strength and durability of the strikeface in the high-impact regions compared to aligning the faceplate's longitudinal grain structure (roll direction) in a low-toe to high-heel (LTHH) direction. However, as the examples below show, HTLH and LTHH grain structure orientations exhibit similar durability. Furthermore, advances in material strength properties have reduced the need for durability increases. Therefore, although sufficient durability is needed, the strikeface CT value carries greater importance for the instant disclosure.

As stated above, there is now a need to focus on creating a uniform CT across the strikeface so that the overall CT value can be raised. Raising the CT value increases shot ball speed. There is also a need in the art for a means of controlling the CT value so that the golf club head remains within the USGA and R&A conformance requirements.

Most golf club heads have metal faceplates intended for striking golf balls. Each metal faceplate is cut from a rolled sheet of metal, which has a directional grain structure aligned with the rolling direction. The metal has different properties along the rolling direction (longitudinal) compared to perpendicular to the rolling direction (transverse). Typically, a faceplate is formed so that the longitudinal grain structure direction (roll direction) of the metal is aligned horizontally in the faceplate. However, some faceplates are cut so that the longitudinal direction of the metal is angled from a high-toe region to a low-heel region (HTLH). Said high-toe to low-heel (HTLH) angulation of the rolled metal allegedly result in an anisotropic faceplate having a greater strength and durability in the high-toe region than a similar club without the angulation of the rolled metal. The prior art teaches HTLH angulation, in part, because players typically hit balls from the low-heel to the high-toe region on the faceplate. The prior art alleges that angulation of the metal grain structure increases the high-toe and low-heel strength and decreases the modulus of elasticity in these regions.

To manufacture a golf club head, a faceplate component is welded to a body component. The faceplate is created by running a unidirectional metal sheet (typically a titanium alloy) through a series of rollers to achieve a desired faceplate thickness. Once run through the rollers, the metal sheet has a directionality along the roller direction. Next, unformed faceplates are cut out of the metal sheet with stamps, punches, or lasers. Then, the unformed faceplates are individually run through a press wherein a set of press dies forms the desired faceplate bulge and thickness. Alternately, the unformed faceplates can be milled to the desired thickness. The faceplate is then laser welded to the body component of the golf club head.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a golf club head, according to one embodiment.

FIG. 2 shows a heel-side view of the golf club head of FIG. 1.

FIG. 3 shows a front view of the golf club head of FIG. 1.

FIG. 4 shows a cross-sectional diagram of material grain structure and its formation during a rolling process.

FIG. 5 shows a second front view of the golf club head of FIG. 1.

FIG. 6 shows a front view of a golf club head, according to an embodiment.

FIG. 7 shows a cross-sectional rear view of the golf club head of FIG. 1, taken along line VII-VII of FIG. 2.

FIG. 8 shows a cross-sectional view of the faceplate of the golf club head of FIG. 7, taken along line VIII-VIII of FIG. 7.

DEFINITIONS

Described herein, the term “anisotropy” means a property of a substance having different physical properties in different axial directions. For example, a component that exhibits different moduli of elasticity or different strength values when measured along different axial directions.

Described herein, the term “characteristic time” (CT) means the amount of time, measured in microseconds, that the strikeface of a club head remains in contact with a metal ball used in a testing apparatus.

As described above, the coefficient of restitution (COR) is the ratio of final relative velocity to initial relative velocity between two objects after they collide. COR is measured as the ratio of the final relative velocity of the golf ball after collision/impact with the club head strikeface to the initial relative velocity of the golf ball prior to collision/impact.

DESCRIPTION

Described herein below is a club head with an anisotropic faceplate, having an intermediate modulus of elasticity value that contributes to more uniform characteristic time (CT) across the faceplate.

The present invention uses low-toe to high-heel (LTHH) angulation of the metal grain structure to increase the high-toe and low-heel modulus of elasticity. The orientation of the material grain structure is determined by the rolling direction of the base material during manufacturing. The present invention orients the directional grain structure (also rolling direction) from low-toe to high-heel (LTHH) to control the modulus value in the high-toe and low-heel regions. Due to the geometry of a golf club head, the high-toe region typically experiences high characteristic time (CT). Increasing the elasticity in the high-toe and low-heel regions, makes these regions less flexible and hot. In this way, the present invention's orientation of the metal grain structure (roll direction) achieves a faceplate having a more balanced or uniform CT across the faceplate. Presented below is a golf club head comprising a faceplate having a metal grain structure that extends from low-toe to high-heel (LTHH).

Referring to FIGS. 1-3, the golf club head 50 described herein can be a wood-type golf club head, such as a driver, a fairway wood, a hybrid, or any other wood-type club head. The golf club head 50 comprises a heel 56, a toe 60 opposite the heel 56, a hosel 58, a crown 52, a sole 54 opposite the crown 52, a rear 62, and a strikeface 64 opposite the rear 62. The strikeface 64 is positioned adjacent and between the sole 54 and the crown 52. The strikeface 64 is configured to withstand impact with a golf ball during a golf swing. The golf club head 50 can comprise a body 98 and a faceplate 68. The faceplate 68 forms at least a portion of the strikeface 64.

Referring to FIG. 3, the strikeface 64 of the club head defines a geometric center 66. In some embodiments, the geometric center 66 can be located at the geometric centerpoint of a strikeface perimeter, and at a midpoint of a height 92 of the strikeface 64. In the same or other examples, the geometric center 66 also can be centered with respect to an engineered impact zone, which can be defined by a region of grooves on the strikeface 64. As another approach, the geometric center 66 of the strikeface 64 can be located in accordance with the definition of a golf governing body such as the United States Golf Association (USGA). For example, the geometric center 66 of the strikeface 64 can be determined in accordance with Section 6.1 of the USGA's Protocol for Measuring the Flexibility of a Golf Clubhead (TPX3004 Rev. 2.0, Apr. 9, 2019) (available at https://www.usga.org/content/dam/usga/pdf/2019/equipment-standards/TPX3004%20Protocol%20for%20Measuring%20the%20Flexibility%20of%20a%20Golf%20Clubhead.pdf).

Referring to FIGS. 2 and 3, the club head 50 further defines a loft plane 12 tangent to the geometric center 66 of the strikeface 64. The face height 92 can be measured parallel to the loft plane 12 between a top end of the strikeface perimeter near the crown 52 and a bottom end of the strikeface perimeter near the sole 54. In these embodiments, the strikeface perimeter can be located along the outer edge of the strikeface 64 where the curvature deviates from the bulge and/or roll of the strikeface 64. A loft angle 14 can be measured as the angulation of the loft plane 12 from a ground plane 10.

Referring to FIG. 3, the strikeface geometric center 66 further defines a coordinate system having an origin located at the strikeface geometric center 66, the coordinate system having a horizontal reference axis 16 and a vertical reference axis 18. The vertical reference axis 18 extends within the loft plane 12, through the strikeface geometric center 66 in a direction from the crown 52 to the sole 54. The horizontal reference axis 16 extends within the loft plane 12, through the strikeface geometric center 66 in a direction from the heel 56 to the toe 60 of the club head 50.

The strikeface 64 further comprises a high-toe region 70, a high-heel region 72, a low-toe region 74, and a low-heel region 76. The high-toe region 70 is defined above the horizontal reference axis 16 and on the toe side of the vertical reference axis 18 (the toe side is closer to the toe 60 than the heel 56). The high-heel region 72 is defined above the horizontal reference axis 16 and on the heel side of the vertical reference axis 18 (the heel side is closer to the heel 56 than the toe 60). The low-toe region 74 is defined below the horizontal reference axis 16 and on the toe side of the vertical reference axis 18. The low-heel region 76 is defined below the horizontal reference axis 16 and on the heel side of the vertical reference axis 18.

The golf club head body 98 can form the crown 52, sole 54, rear 62, toe 60, and at least a portion of the heel 56. In some embodiments, the body 98 further forms at least a portion of the strikeface 64. In some embodiments, the body 98 comprises a front opening that receives the faceplate 68. The faceplate 68 can be welded, swedged (swagged), or otherwise secured to the body 98. The body 98 can integrally comprise weighted portions and/or be configured to receive at least one removable weight. The body 98 of the golf club head 50 can be formed from a metal alloy material or a polymer composite material.

In many embodiments, for example, those comprising driver club heads, the loft angle 14 of the club head 50 is less than approximately 16 degrees, less than approximately 15 degrees, less than approximately 14 degrees, less than approximately 13 degrees, less than approximately 12 degrees, less than approximately 11 degrees, or less than approximately 10 degrees. Further, in many embodiments, the volume of the club head is greater than approximately 400 cc, greater than approximately 425 cc, greater than approximately 450 cc, greater than approximately 475 cc, greater than approximately 500 cc, greater than approximately 525 cc, greater than approximately 550 cc, greater than approximately 575 cc, greater than approximately 600 cc, greater than approximately 625 cc, greater than approximately 650 cc, greater than approximately 675 cc, or greater than approximately 700 cc. In some embodiments, the volume of the club head 50 can be approximately 400 cc-600 cc, 425 cc-500 cc, approximately 500 cc-600 cc, approximately 500 cc-650 cc, approximately 550 cc-700 cc, approximately 600 cc-650 cc, approximately 600 cc-700 cc, or approximately 600 cc-800 cc.

In many embodiments, for example, those comprising fairway wood-type club heads, the loft angle 14 of the club head 50 is less than approximately 35 degrees, less than approximately 34 degrees, less than approximately 33 degrees, less than approximately 32 degrees, less than approximately 31 degrees, or less than approximately 30 degrees. Further, in many embodiments, the loft angle of the club head is greater than approximately 12 degrees, greater than approximately 13 degrees, greater than approximately 14 degrees, greater than approximately 15 degrees, greater than approximately 16 degrees, greater than approximately 17 degrees, greater than approximately 18 degrees, greater than approximately 19 degrees, or greater than approximately 20 degrees. For example, in some embodiments, the loft angle of the club head can be between 12 degrees and 35 degrees, between 15 degrees and 35 degrees, between 20 degrees and 35 degrees, or between 12 degrees and 30 degrees.

In many embodiments, for example, those comprising fairway wood-type club heads, the volume of the club head 50 is less than approximately 400 cc, less than approximately 375 cc, less than approximately 350 cc, less than approximately 325 cc, less than approximately 300 cc, less than approximately 275 cc, less than approximately 250 cc, less than approximately 225 cc, or less than approximately 200 cc. In some embodiments, the volume of the club head can be approximately 150 cc-200 cc, approximately 150 cc-250 cc, approximately 150 cc-300 cc, approximately 150 cc-350 cc, approximately 150 cc-400 cc, approximately 300 cc-400 cc, approximately 325 cc-400 cc, approximately 350 cc-400 cc, approximately 250 cc-400 cc, approximately 250-350 cc, or approximately 275-375 cc.

In many embodiments, for example, those comprising hybrid-type club heads, the loft angle 14 of the club head 50 is less than approximately 40 degrees, less than approximately 39 degrees, less than approximately 38 degrees, less than approximately 37 degrees, less than approximately 36 degrees, less than approximately 35 degrees, less than approximately 34 degrees, less than approximately 33 degrees, less than approximately 32 degrees, less than approximately 31 degrees, or less than approximately 30 degrees. Further, in many embodiments, the loft angle of the club head is greater than approximately 16 degrees, greater than approximately 17 degrees, greater than approximately 18 degrees, greater than approximately 19 degrees, greater than approximately 20 degrees, greater than approximately 21 degrees, greater than approximately 22 degrees, greater than approximately 23 degrees, greater than approximately 24 degrees, or greater than approximately 25 degrees.

In many embodiments, for example, those comprising hybrid-type club heads, the volume of the club head 50 is less than approximately 200 cc, less than approximately 175 cc, less than approximately 150 cc, less than approximately 125 cc, less than approximately 100 cc, or less than approximately 75 cc. In some embodiments, the volume of the club head can be approximately 100 cc-150 cc, approximately 75 cc-150 cc, approximately 100 cc-125 cc, or approximately 75 cc-125 cc.

Metal Grain Structure of Faceplate

Referring to FIG. 4, the faceplate material of the golf club head comprises a directional grain structure. The alloy metal microstructure is made of grains (or units) 30 that can be formed in a circular (or “equiaxed”) fashion. As described below, the directional grain structure is formed during the rolling process, which turns a metal slab into a thinner sheet form. During rolling, the grains 30 themselves are flattened and elongated during the rolling process, creating elongated grains 32. This sheet is used to form the faceplate and the long axis of the elongated grains 32 are aligned in roughly the same direction within the faceplate 68. In some embodiments, the elongated grains 32 are aligned within between 0-10 degrees, between 0-20 degrees, or between 0-30 degrees of each other. The average angle of the elongated grains 32 defines the orientation of the directional grain structure. The directional grain structure causes the faceplate to exhibit anisotropy.

Referring to FIGS. 5 and 6, the orientation of the directional grain structure is known as the longitudinal (“L”) direction 20. In other words, the elongated grains of the directional grain structure are oriented in the longitudinal L direction 20. The longitudinal L direction 20 corresponds to the direction in which the faceplate material is rolled during manufacturing. A transverse direction (“T”) 22 is perpendicular to the longitudinal L direction 20.

Referring to FIG. 5, the L direction 20 of the faceplate material can be aligned so that it is angularly offset from the horizontal reference axis 16 by an offset angle θ. The offset angle θ is measured counterclockwise from the horizontal reference axis 16. The offset angle θ can be greater than 0 and less than 90 degrees (0<0<90 degrees). In some embodiments, the offset angle θ can range between 5 degrees and 85 degrees. In some embodiments, the offset angle θ can range between 10 and 80 degrees, 20 and 70 degrees, 30 and 60 degrees, 40 and 50 degrees, between 35 and 55 degrees, between 5 and 45 degrees, or between 45 and 85 degrees. In some embodiments, the offset angle θ can be 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees, or 85 degrees. The offset angle θ determines the material properties of the strikeface 64 along the horizontal and the vertical reference axes 16, 18 of the club head 50.

The faceplate material can comprise a modulus of elasticity ranging between 98.5 GPa and 151.7 GPa (14 Mpsi-22 Mpsi). Due to the anisotropy of the faceplate 64, the modulus of elasticity differs between the longitudinal L direction 20 and the traverse T direction 22. The modulus of elasticity measured in the L direction 20 is lower than the modulus of elasticity measured in the T direction 22. The modulus of elasticity in the L direction 20 can range between 98.5 GPa and 151.7 GPa (14 Mpsi-22 Mpsi). In some embodiments, the modulus of elasticity in the L direction 20 can be 98 GPa, 99 GPa, 100 GPa, 101 GPa, 102 GPa, 103 GPa, 104 GPa, 105 GPa, 106 GPa, 107 GPa, 108 GPa, 109 GPa, 110 GPa, 111 GPa, 112 GPa, 113 GPa, 114 GPa, 115 GPa, 116 GPa, 117 GPa, 118 GPa, 119 GPa, 120 GPa, 121 GPa, 122 GPa, 123 GPa, 124 GPa, 125 GPa, 126 GPa, 127 GPa, 128 GPa, 129 GPa, 130 GPa, 132 GPa, 134 GPa, 126 GPa, 128 GPa, 130 GPa, 132 GPa, 134 GPa, 136 GPa, 138 GPa, 140 GPa, 142 GPa, 144 GPa, 146 GPa, 148 GPa, or 150 GPa. The modulus of elasticity in the T direction 22 can range between 118 GPa and 146 GPa (17.11 Mpsi-21.17 Mpsi). In some embodiments, the modulus of elasticity in the T direction 22 can be between 118 GPa and 122 GP, 122 GPa and 126 GPa, 126 GPa and 130 GPa, 130 GPa and 134 GPa, 134 GPa and 138 GPa, 138 GPa and 142 GPa, or 142 GPa and 146 GPa.

Additionally, the modulus of elasticity can be measured along any direction between the L and T directions 20, 22. By nature of the material structure, the modulus of elasticity along a direction between the L and T directions has a value between the modulus of elasticity in the L direction 20 and the modulus of elasticity in the T direction 22. The modulus of elasticity measured at 45 degrees from the L direction 20 (between the L and T directions) can range between 110 GPa and 131 GPa (16 Mpsi-19 Mpsi). In some embodiments, the modulus of elasticity measured at 45 degrees from the L direction 20 can range between 110 GPa and 130 GPa, 110 GPa and 120 GPa, 113 GPa and 119 GPa, or 118 GPa and 125 GPa. In some embodiments, the modulus of elasticity measured at 45 degrees from the L direction 20 can be 110 GPa, 111 GPa, 112 GPa, 113 GPa, 114 GPa, 115 GPa, 116 GPa, 117 GPa, 118 GPa, 119 GPa, 120 GPa, 121 GPa, 122 GPa, 123 GPa, 124 GPa, 125 GPa, 126 GPa, 127 GPa, 128 GPa, 129 GPa, 130 GPa, or 131 GPa.

In the embodiment of FIG. 6, the faceplate material longitudinal L direction 20 is aligned with the horizontal reference axis 16 of the club head 50. The transverse T direction 22 of the faceplate material is aligned with the vertical reference axis 18 of the club head 50. In this embodiment, the modulus of elasticity in the horizontal reference axis direction 16 will be lower than the modulus of elasticity measured in the vertical reference axis direction 18. The horizontal modulus of elasticity (along the width 90) has a greater effect on faceplate flexibility than the vertical modulus of elasticity (along the height 92), because the faceplate's width 90 is greater than the faceplate's height 92. Therefore, a faceplate 68 having a lower horizontal modulus of elasticity than vertical modulus of elasticity will flex or bend more freely than faceplates lacking this anisotropic property/configuration. For example, consider a golf club head (not shown) wherein the faceplate material longitudinal L direction 20 is aligned with the vertical reference axis 18 of the club head 50, and the transverse T direction 22 is aligned with the horizontal reference axis 16. In this golf club head 50, the horizontal modulus of elasticity (along the width 90) will be higher than the vertical modulus of elasticity (along the height 92). Therefore, this faceplate 68 would flex or bend less, and transfer less energy back to an impacted golf ball.

The offset angle θ can be altered to control the modulus of elasticity in the horizontal direction. As described above, an increase in the modulus of elasticity will lower CT, while a decrease in the modulus of elasticity will raise CT. Therefore, altering the offset angle θ indirectly controls the CT of the strikeface. Angularly offsetting the directional grain structure of the faceplate material so that it is off-axis (that is angled from the horizontal reference axis 16), allows the strikeface 64 to exhibit a horizontal modulus of elasticity value that is in-between the material longitudinal L direction 20 modulus and the transverse T direction 22 modulus. In some embodiments, a faceplate with an offset angle θ of approximately 45 degrees can exhibit a horizontal modulus of elasticity between 116 GPa and 130 GPa, 116 GPa and 120 GPa, 117 GPa and 119 GPa, or 118 GPa and 125 GPa.

A faceplate with a steeper (greater) offset angle θ exhibits a higher modulus of elasticity in the horizontal reference axis direction 16 than a faceplate with a shallower (lesser) offset angle θ. A faceplate with a shallower (lesser) offset angle θ exhibits a lower modulus of elasticity in the horizontal reference axis direction 16 than a faceplate with a steeper (greater) offset angle θ. A steeper (greater) offset angle θ will result in a lower CT than a shallower (lesser) offset angle θ. A shallower (lesser) offset angle θ will result in a higher CT than a steeper (greater) offset angle θ. Therefore, the offset angle θ can be set/designed at a value that retains the CT value below the required threshold set by the USGA (239 μs+/−18 μs across impact area).

In addition to controlling overall CT of the strikeface 64, in some embodiments, the off-axis directional grain structure can also locally control CT within regions of the strikeface 64. The geometry of a golf club head 50 causes a strikeface 64 to have points of higher and lower CT across the strikeface 64. Typically, the high-toe region 70 exhibits the highest CT values. To maximize the energy transferred to an impacted golf ball, the CT must be as high as possible at all points on the strikeface 64, not only in the high-toe region 70. Angling the faceplate longitudinal L direction 20 from the low-toe region 74 towards the high-heel region 72, causes the low-heel region 76 and the high-toe region 70 to have lower CT values than the low-toe region 74 and high-heel region 72. Angling the directional grain structure from the low-toe region 74 to the high-heel region 72 (at an offset angle θ), encourages a more uniform CT across the strikeface 64 since it lowers the CT in the hottest high-toe region 70 of the strikeface 64.

To quantify the uniformity of the CT across the strikeface 64, a CT differential can be measured as the difference between a maximum CT and a minimum CT of the strikeface 64. A strikeface with a directional grain structure aligned parallel with the horizontal reference axis 16 (i.e. a heel-to-toe alignment) can comprise a CT differential across the face of greater than or equal to 5 μs. In some embodiments, the CT differential for a heel-to-toe directional grain structure can be between 5-10 μs. In comparison, a strikeface 64 with a directional grain structure angled at an offset angle θ of 45 degrees, can comprise a CT differential of less than or equal to 5 μs, less than or equal to 4 μs, less than or equal to 3 μs, or between 0-5 μs. In some embodiments, the CT differential for the herein described strikeface 64 can range between 0-1 μs, 1-2 μs, 2-3 μs, 3-4 μs, or 4-5 μs. In some embodiments, the CT differential can be 0 μs, 1 μs, 2 μs, 3 μs, 4 μs, or 5 μs.

By creating a more uniform CT across the face, the overall CT can be increased without breaching the USGA pendulum test requirements. More specifically, in some embodiments, the CT at the geometric center 66 and/or sweet spot of the strikeface 64 can be increased. In some embodiments, the off-axis alignment of the directional grain structure, with offset angle θ>0, can provide a ball speed increase of between 0.25 and 5 mph (compared to a horizontal grain structure strikeface, with offset angle θ=0). In some embodiments, the off-axis alignment of the directional grain structure allows for a ball speed increase of ¼ mph, ½ mph, ¾ mph, 1 mph, 1.5 mph, 2 mph, 2.5 mph, 3 mph, 3.5 mph, 4 mph, 4.5 mph, 5 mph, or any value therebetween.

The faceplate 68 can be formed from a metal alloy, such as a steel, a titanium alloy, or any other suitable metal material. In some embodiments, the faceplate material is a steel alloy, such as C300 steel, C350 steel, 455 steel, 431 steel, 475 steel, 565 steel, 17-4 stainless steel, maraging steel, Ni—Co—Cr steel alloy, AerMet 310 steel, or AerMet 340 steel. In some embodiments, the faceplate material is an a-P titanium (a-P Ti) alloy. The a-P Ti alloy may contain neutral alloying elements such as tin and a stabilizers such as aluminum and oxygen. The a-P Ti alloy may contain P-stabilizers such as molybdenum, silicon and vanadium. All numbers described below regarding weight percent are a total weight percent (wt %). The total weight percent of a-stabilizer aluminum in a-P Ti alloy may be between 2 wt % to 10 wt %, 3 wt % to 9 wt %, 4 wt % to 8 wt %, 5 wt % to 7 wt %, 2 wt % to 20 wt %, 3 wt % to 19 wt %, 4 wt % to 18 wt %, 5 wt % to 17 wt %, 6 wt % to 16 wt %, 7 wt % to 15 wt %, 8 wt % to 14 wt %, 9 wt % to 13 wt %, 10 wt % to 12 wt %, 7 wt % to 9 wt %, 7 wt % to 10 wt %, 7 wt % to 11 wt %, 7 wt % to 12 wt %, 7 wt % to 13 wt %, 7 wt % to 14 wt %, 7 wt % to 15 wt %, 7 wt % to 16 wt %, 7 wt % to 17 wt %, 7 wt % to 18 wt %, 7 wt % to 19 wt %, 7 wt % to 20 wt %, 8 wt % to 10 wt %, 8 wt % to 11 wt %, 8 wt % to 12 wt %, 8 wt % to 13 wt %, 8 wt % to 14 wt %, 8 wt % to 15 wt %, 8 wt % to 16 wt %, 8 wt % to 17 wt %, 8 wt % to 18 wt %, 8 wt % to 19 wt %, 8 wt % to 20 wt %, 9 wt % to 11 wt %, 9 wt % to 12 wt %, 9 wt % to 13 wt %, 9 wt % to 14 wt %, 9 wt % to 15 wt %, 9 wt % to 16 wt %, 9 wt % to 17 wt %, 9 wt % to 18 wt %, 9 wt % to 19 wt %, 9 wt % to 20 wt %, 10 wt % to 13 wt %, 10 wt % to 14 wt %, 10 wt % to 15 wt %, 10 wt % to 16 wt %, 10 wt % to 17 wt %, 10 wt % to 18 wt %, 10 wt % to 19 wt %, 10 wt % to 20 wt %, 11 wt % to 13 wt %, 11 wt % to 14 wt %, 11 wt % to 15 wt %, 11 wt % to 16 wt %, 11 wt % to 17 wt %, 11 wt % to 18 wt %, 11 wt % to 19 wt %, 11 wt % to 20 wt %, 12 wt % to 14 wt %, 12 wt % to 15 wt %, 12 wt % to 16 wt %, 12 wt % to 17 wt %, 12 wt % to 18 wt %, 12 wt % to 19 wt %, 12 wt % to 20 wt %, 13 wt % to 15 wt %, 13 wt % to 16 wt %, 13 wt % to 17 wt %, 13 wt % to 18 wt %, 13 wt % to 19 wt %, 13 wt % to 20 wt %, 14 wt % to 16 wt %, 14 wt % to 17 wt %, 14 wt % to 18 wt %, 14 wt % to 19 wt %, 14 wt % to 20 wt %, 15 wt % to 17 wt %, 15 wt % to 18 wt %, 15 wt % to 19 wt %, 15 wt % to 20 wt %, 16 wt % to 18 wt %, 16 wt % to 19 wt %, 16 wt % to 20 wt %, 17 wt % to 19 wt %, 17 wt % to 20 wt %, or 18 wt % to 20 wt %.

In certain embodiments, the total weight percent of a-stabilizer aluminum in a-P Ti alloy may be between 7 wt % to 13 wt %, 8 wt % to 13 wt %, 9 wt % to 13 wt %, 10 wt % to 13 wt %, 11 wt % to 13 wt %, or 12 wt % to 13 wt %. The total weight percent of a-stabilizer oxygen in a-P Ti alloy may be between 0.05 wt % to 0.35 wt %, or 0.10 wt % to 0.20 wt %. The total weight percent of 0-stabilizer molybdenum in a-P Ti alloy may be between 0.2 wt % to 1.0 wt %, or 0.6 wt % to 0.8 wt %, or trace amounts. The total weight percent of P-stabilizer vanadium in a-P Ti alloy may be between 1.5 wt % to 7 wt %, or 3.5 wt % to 4.5 wt %. The total weight percent of P-stabilizer silicon in a-P Ti alloy may be between 0.01 to 0.10 wt %, or 0.03 wt % to 0.07 wt %. The a-P Ti alloy may be Ti-6Al-4V (or Ti 6-4), Ti-7S+(or Ti-7S, T-7S, or ST721), Ti-9S (or T-9S), Ti-9S+, HST-180, FS2S, Super-TiX 51AF, Super-TiX 51 Premium, Ti-662, Ti-8-1-1, Ti-65K, Ti-6246, or IMI 550.

Referring to FIGS. 7 and 8, to provide region-specific strength and uniform CT, some embodiments of the club head 50 described herein can also comprise a varying thickness across the strikeface 64. The strikeface 64 comprises an inner surface 84 and an outer surface 86. A strikeface thickness 88 is measured between the inner surface 84 and the outer surface 86, perpendicular to the loft plane 12. The strikeface thickness 88 can differ between regions of the strikeface 64. The strikeface 64 can comprise a central region 78 overlapping a sweet spot and/or the geometric center 66 of the strikeface 64, a transition region 80 adjacent and surrounding the central region 78, and a peripheral region 82 adjacent and surrounding the transition region 80. The peripheral region 82 of the strikeface 64 can be adjacent the toe 60, heel 56, crown 52, and sole 54 edges of the club head 50. The central region 78 can have a thickness 88 greater than the transition region 80 and/or the peripheral region 82 of the strikeface 64. The peripheral region 82 of the strikeface 64 can be the thinnest portion of the strikeface 64. The thickness differences between the regions of the strikeface 64 can cause the inner surface 84 of the strikeface 64 to be non-planar. In some embodiments, the variable face thickness of the strikeface 64 results in an oval-shaped or egg-shaped thickened region. The position and shape of this thickened region can provide additional CT control by reducing the CT within the thickened region.

A minimum thickness of the strikeface 64 can be between 1.5 millimeters (0.059 inch) and 0.4 millimeters (0.016 inch). In some embodiments, the minimum thickness of the strikeface 64 can be 1.5 millimeters, 1.4 millimeters, 1.3 millimeters, 1.2 millimeters, 1.1 millimeters, 1.0 millimeters, 0.9 millimeters, 0.8 millimeters, 0.7 millimeters, 0.6 millimeters, 0.5 millimeters, or 0.4 millimeters.

A maximum thickness of the strikeface 64 can be between 1.5 millimeters (0.059 inch) and 5 millimeters (0.197 inch). In some embodiments, the maximum thickness of the strikeface can be between 1.5 millimeters and 3.0 millimeters, 3.0 millimeters and 4.0 millimeters, 3.2 millimeters and 4.2 millimeters, 3.4 millimeters and 4.4 millimeters, or greater than 4.4. millimeters.

The strikeface 64 can further comprise a curvature defined by a bulge radius and roll radius. The bulge radius is measured in a toe-to-heel direction across the strikeface 64 and can range between 8 and 14 inches. In some embodiments, the bulge radius can be 8 inches, 9 inches, 10 inches, 11 inches, 12 inches, 13 inches, or 14 inches. The roll radius is measured in a crown-to-sole direction across the strikeface 64 and can range between 7 and 15 inches. In some embodiments, the roll radius is 7 inches, 8 inches, 9 inches, 10 inches, 11 inches, 12 inches, 13 inches, 14 inches, or 15 inches. In some embodiments, the bulge and roll radii are constant across the strikeface 64, but in other embodiments one or both of the bulge and roll radii vary across the strikeface. The formation of the bulge and roll radii negligibly affects the grain structure of the strikeface material.

Method of Manufacture

To produce the faceplate 68, a sheet of the desired strikeface material is subject to a rolling process. The raw material comprises an equiaxed grain structure. The raw material sheet is pressed and forced between two opposing rollers to reduce the thickness of the sheet. This rolling process is repeated multiple times in the same direction, until the desired sheet thickness is reached. The sheets are typically rolled 2 to 15 times. The repeated rolling alters the grain structure of the material, causing the equiaxed grains to deform into elongated grains. The elongated grains are oriented in the direction that the rolling occurs.

The rolling process can be done as a cold rolling process or a hot rolling process. A hot rolling process is done with material temperatures over 200 degrees Centigrade. Hot rolling is often done between 700 and 1000 degrees Centigrade. A cold rolling process is done with material temperatures under 200 degrees Centigrade. Cold rolling can be done at any temperature between 0 and 200 degrees Centigrade. In some embodiments, the faceplate 64 is formed by a combination of hot rolling and cold rolling. A hot rolling process can be repeated 2 to 7 times. Next, a cold rolling process can be repeated 5 to 7 times. The sheets are not annealed or heat treated after rolling, because further processing the material at a high temperature could alter or destroy the elongated grain structure.

After the rolling of the sheet material, one or more faceplates can be stamped, laser cut, or punched from the sheet material. In some embodiments, the one or more faceplates are milled, either prior to or after stamping. The inner surface of each faceplate can be milled to create the variable face thickness. Once the faceplate is prepared, it can be attached into a receiving opening on the body of the club head. The club head body can be cast, forged, or otherwise produced. The faceplate can be welded or swedged (swagged) into the receiving opening of the body.

The sheets which are rolled prior to the stamping of the faceplates have set width and length dimensions. Angling the faceplates allows more faceplates to be produced from each sheet, thus reducing waste metal. For example, when the faceplates are stamped so that the grain structure is oriented with the longitudinal L direction running heel to toe, approximately 504 faceplates can be stamped out of each sheet. However, when the faceplates are stamped so that the grain structure is oriented at a 45 degree angle (LTHH or HTLH), each sheet yields 540 faceplates. Therefore, the angled grain structure not only helps with CT control, but also reduces waste and manufacturing cost.

Example 1

A CT comparison test was done between a control set of faceplates, a first set of example faceplates, a second set of example faceplates, and a third set of example faceplates. The control set of faceplates comprised a heel-to-toe oriented directional grain structure. The first set of example faceplates comprised a crown-to-sole oriented directional grain structure. The second set of example faceplates comprised a low-toe to high-heel (LTHH) oriented directional grain structure. The third set of example faceplates comprised a high-toe to low-heel (HTLH) oriented directional grain structure. Each of the sets of faceplates (control, first, second, and third) comprised five faceplates. The control, first, second, and third sets of faceplates were all formed from T9S+ titanium alloy material.

Every faceplate within the control, first, second, and third sets of faceplates comprised the same face thickness profile. The faceplates comprised a variable face thickness, with a minimum thickness of 0.089 inch (2.26 mm) and a maximum thickness of 0.139 inch (3.53 mm).

Measurements were taken of the average CT at the geometric center of each faceplate and the average CT in the high-toe region of the faceplate. The first, second, and third sets of example faceplates comprised average CT values lower than the control set at both the geometric center and in the high-toe region. Table I, below, presents the results of the CT comparison.

TABLE I Example 1 CT Results Control First Second Third (heel-to-toe) (crown-to-sole) (LTHH) (HTLH) Center CT Avg 244.3 237.6 238.4 238.0 High Toe CT Avg 250.2 242.6 242.4 241.6 CT Differential 5.9 5.0 4.0 3.6

The first, second, and third sets of example faceplates exhibited lower CT without compromising the durability of the faceplates. Orienting the directional grain structure of the faceplate material at an offset angle from the horizontal reference axis reduces the CT. Using directional grain structure to control CT can prevent the faceplate from exceeding the maximum CT limit for conformance (239 μs+/−18 μs). Additionally, the second (LTHH) and third (HTLH) sets of example faceplates exhibited lower CT differentials than the control (heel-to-toe) and first (crown-to-sole) sets. Therefore, the second and third faceplate sets would both provide a golfer with a more uniform response across the face and allow the golf club designer to raise the average CT through other club head technologies without exceeding the USGA CT limit.

Example 2

A durability test was done between a control set and a first, second, and third set of example faceplates, similar to the first, second, and third sets of example faceplates introduced in Example 1 above. The first set of example faceplates comprised a crown-to-sole oriented directional grain structure. The second set of example faceplates comprised a low-toe to high-heel (LTHH) oriented directional grain structure. The third set of example faceplate comprised a high-toe to low-heel (HTLH) oriented directional grain structure. All the example faceplate sets were formed from T9S+ titanium alloy material. In this durability test, each of the sets of faceplates (first, second, and third) comprised three faceplates.

Every faceplate within the control, first, second, and third sets of faceplates comprised the same face thickness profile. The faceplates comprised a variable face thickness, with a minimum thickness of 2.26 mm (0.089 inch) and a maximum thickness of 3.53 mm (0.139 inch).

The control, the first, second, and third sets of example faceplates were each repeatedly impacted by a golf ball traveling at a speed of approximately 120 mph. The testing was conducted using an air cannon system. The number of hits to failure was tested for the each faceplate set. The control set endured on average approximately 2700 hits from a golf ball traveling at approximately 120 mph before failure. The first set of example faceplates endured on average approximately 1400 hits from a golf ball traveling at approximately 120 mph before failure. The second set of example faceplates (LTHH) endured on average approximately 2150 hits from a golf ball traveling at approximately 120 mph before failure. The third set of example faceplates (HTLH) endured on average approximately 2120 hits from a golf ball traveling at approximately 120 mph before failure. Therefore, both the second set of example faceplates, having low-toe to high-heel oriented directional grain structure, and the third set of example faceplates, having high-toe to low-heel oriented directional grain structure, were more durable than the first set of example faceplates, having crown-to-sole oriented directional grain structure. Although the control set was slightly more durable than the second and third sets of example faceplates, any faceplate that endures 2000 hits or more without failure is considered highly durable and suitable for professional performance.

The durability of the second and third sets differed by less than 8 shots out of over 2100 shots. Therefore, this durability test revealed that faceplates with a low-toe to high-heel (LTHH) oriented directional grain structure and faceplates with a high-toe to low-heel (HTLH) oriented directional grain structure exhibit roughly equivalent durability. Combining this knowledge with the results from Example 1 above, an angled grain structure (either LTHH or HTLH) maintains sufficient durability (over 2000 hits at 120 mph), while also beneficially reducing the CT value.

Durability

Golfers hit most often within the low-heel region and/or high-toe region of the strikeface. The mechanics of a golf swing causes this higher probability of hits within the low-heel region and high-toe region. A dispersion of shots across a strikeface often falls within an elliptical region whose major axis is angled from the low-heel region to the high-toe region. In some embodiments, this elliptical hit region major axis (not shown) is angled clockwise from the horizontal reference axis by between 0 and 90 degrees. To maintain long-term durability of a strikeface, the faceplate material must be strong enough to withstand these hit impacts. In theory. the strength of the faceplate material is greater along the longitudinal L direction than along the transverse T direction. Therefore, in prior art club heads, the longitudinal L direction has been aligned from the high-toe region to the low-heel region (HTLH). In other words, the longitudinal L direction has been aligned approximately parallel to the major axis of the elliptical mishit region. However, as shown in Example 2 below, in actuality, a faceplate with the longitudinal L direction aligned low-toe to high heel (LTHH) exhibits equal or greater durability than a faceplate with the longitudinal L direction aligned high-toe to low-heel (HTLH).

Aligning the longitudinal L direction of the grain structure in either a LTHH or HTLH direction results in a durability that is greater than the durability exhibited by a faceplate with the longitudinal L direction aligned crown to sole. In some embodiments, faceplates with LTHH or HTLH orientations are able to withstand up to 30% more hits, 40% more hits, 50% more hits, 60% more hits, or 70% more hits than a faceplate with a crown to sole oriented grain structure.

Although aligning the longitudinal L direction of the grain structure in either a LTHH or HTLH direction reduces the durability compared to a heel to toe alignment, the LTHH and HTLH orientations maintain sufficient durability to withstand up to at least 2000 hits without failure.

The herein described low-toe to high-heel (LTHH) angulation of the faceplate material increases the modulus of elasticity within the high-toe and low-heel regions. This increase of the modulus of elasticity within the high-toe and low-heel regions reduces the CT within said regions and thus lowers the CT differential across the strikeface. The lower CT differential allows the overall CT or the CT at the geometric center to be raised without any region within the strikeface impact area reaching the maximum CT limit for conformance (239 μs+/−18 μs). A higher overall CT and/or a higher CT at the geometric center of the strikeface can increase the rebound and ball speed potential of the strikeface. In addition to providing an increase in the rebound properties of the overall strikeface, the uniform CT (low CT differential) causes the herein described club head to respond to impact more consistently, regardless of the region of the strikeface that is impacted. This consistency allows a golfer to more accurately predict where his or her shot will land and/or the distance a shot will travel.

As the rules to golf may change from time to time (e.g., new regulations may be adopted or old rules may be eliminated or modified by golf standard organizations and/or governing bodies), golf equipment related to the methods, apparatus, and/or articles of manufacture described herein may be conforming or non-conforming to the rules of golf at any particular time. Accordingly, golf equipment related to the methods, apparatus, and/or articles of manufacture described herein may be advertised, offered for sale, and/or sold as conforming or non-conforming golf equipment. The methods, apparatus, and/or articles of manufacture described herein are not limited in this regard.

Although a particular order of actions is described above, these actions may be performed in other temporal sequences. For example, two or more actions described above may be performed sequentially, concurrently, or simultaneously. Alternatively, two or more actions may be performed in reversed order. Further, one or more actions described above may not be performed at all. The apparatus, methods, and articles of manufacture described herein are not limited in this regard.

While the invention has been described in connection with various aspects, it will be understood that the invention is capable of further modifications. This application is intended to cover any variations, uses or adaptation of the invention following, in general, the principles of the invention, and including such departures from the present disclosure as come within the known and customary practice within the art to which the invention pertains. 

What is claimed is:
 1. A golf club head comprising: a club head body comprising, a heel, a toe, a crown, a sole, a rear, and a strikeface positioned adjacent the sole and the crown and opposite the rear; wherein: the club head further comprises a loft plane tangent to the strikeface; the strikeface comprises: a geometric center; a horizontal reference axis extending from the toe to the heel within the loft plane and through the geometric center of the strikeface; a faceplate; the faceplate comprises a directional grain structure formed of elongated grains oriented on average in a longitudinal L direction; the longitudinal L direction is angularly offset from the horizontal reference axis by an offset angle θ of between 5 and 85 degrees; and the offset angle θ is measured counterclockwise from the horizontal reference axis.
 2. The golf club head of claim 1, wherein the offset angle θ is selected from the group consisting of: between 20 and 70 degrees, between 35 and 55 degrees, between 5 and 45 degrees, and between 45 and 85 degrees.
 3. The golf club head of claim 1, wherein the offset angle θ is selected from the group consisting of: 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees, and 85 degrees.
 4. The golf club head of claim 1, wherein the faceplate comprises a titanium alloy material selected from the group consisting of: Ti-6A1-4V (or Ti 6-4), Ti-7S+(or Ti-7S, T-7S, or ST721), Ti-9S (or T-9S), Ti-9S+, HST-180, FS2S, Super-TiX 51AF, Super-TiX 51 Premium, Ti-662, Ti-8-1-1, Ti-65K, Ti-6246, and IMI
 550. 5. The golf club head of claim 1, wherein the faceplate comprises a steel material selected from the group consisting of: C300 steel, C350 steel, 455 steel, 431 steel, 475 steel, 565 steel, 17-4 stainless steel, maraging steel, Ni—Co—Cr steel alloy, AerMet 310 steel, and AerMet 340 steel.
 6. The golf club head of claim 1, wherein the elongated grains are oriented within 0 to 30 degrees of each other.
 7. The golf club head of claim 1, wherein: the strikeface further comprises an inner surface and an outer surface; the strikeface further comprises a thickness measured between the inner surface and the outer surface, perpendicular to the loft plane; and the thickness varies across the strikeface.
 8. The golf club head of claim 7, wherein: the strikeface further comprises a central region, a transition region surrounding the central region, and a peripheral region surrounding the transition region; the thickness of the central region is greater than the thickness of the peripheral region; and the thickness of the transition region varies.
 9. The golf club head of claim 7, wherein a minimum thickness of the strikeface is between 1.5 mm and 0.4 mm.
 10. The golf club head of claim 7, wherein the central region comprises an elliptical or egg-shaped boundary.
 11. The golf club head of claim 1, wherein the characteristic time (CT) of the golf club head is lower than a similar golf club head lacking a directional grain structure oriented at the offset angle θ of between 5 and 85 degrees.
 12. The golf club head of claim 1, wherein: the golf club head comprises a characteristic time (CT) differential of between 0 and 7 μs, and the characteristic time differential is measured as the difference between a maximum characteristic time (CT) of the strikeface and a minimum characteristic time (CT) of the strikeface.
 13. The golf club head of claim 1, wherein: the faceplate further comprises a transverse T direction oriented perpendicular to the longitudinal L direction; the faceplate comprises a longitudinal modulus of elasticity measured in the longitudinal L direction and a transverse modulus of elasticity measured in the transverse T direction; and the longitudinal modulus of elasticity is lower than the transverse modulus of elasticity.
 14. The golf club head of claim 13, wherein: the longitudinal modulus of elasticity ranges between 108 GPa and 118 GPa (15.66 Mpsi and 17.11 Mpsi); and the transverse modulus of elasticity ranges between range between 118 GPa and 146 GPa (17.11 Mpsi-21.17 Mpsi).
 15. The golf club head of claim 1, wherein: the offset angle θ is approximately 45 degrees; and the modulus of elasticity taken along the horizontal reference axis is between 116 GPa and 130 GPa.
 16. A golf club head comprising: a club head body comprising, a heel, a toe, a crown, a sole, a rear, and a strikeface positioned adjacent the sole and the crown and opposite the rear; wherein: the club head further comprises a loft plane tangent to the strikeface; the strikeface comprises: a geometric center; a vertical reference axis extending from the crown to the sole within the loft plane and through the geometric center of the strikeface; a horizontal reference axis extending from the toe to the heel within the loft plane and through the geometric center of the strikeface; a high-toe region defined above the horizontal reference axis and on a toe side of the vertical reference axis; a high-heel region defined above the horizontal reference axis and on a heel side of the vertical reference axis; a low-toe region defined below the horizontal reference axis and on a toe side of the vertical reference axis; a low-heel region defined below the horizontal reference axis and on a heel side of the vertical reference axis; and a metal material with a directional grain structure that is oriented in a direction from the low-heel region to the high-toe region.
 17. The golf club head of claim 16, wherein: the strikeface comprises a faceplate; the faceplate further comprises a transverse T direction oriented perpendicular to the longitudinal L direction; the faceplate comprises a longitudinal modulus of elasticity measured in the longitudinal L direction and a transverse modulus of elasticity measured in the transverse T direction; and the longitudinal modulus of elasticity is lower than the transverse modulus of elasticity.
 18. The golf club head of claim 16, wherein: the golf club head comprises a characteristic time (CT) differential of between 0 and 7 μs, and the characteristic time differential is measured as the difference between a maximum characteristic time (CT) of the strikeface and a minimum characteristic time (CT) of the strikeface.
 19. The golf club head of claim 16, wherein the angled orientation of the directional grain structure causes a reduction in the characteristic time (CT) of the high-toe region, compared to a club head comprising a strikeface having a horizontal-oriented directional grain structure.
 20. The golf club head of claim 16, wherein the strikeface comprises a titanium alloy material selected from the group consisting of: Ti-6A1-4V (or Ti 6-4), Ti-7S+(or Ti-7S, T-7S, or ST721), Ti-9S (or T-9S), Ti-9S+, HST-180, FS2S, Super-TiX 51AF, Super-TiX 51 Premium, Ti-662, Ti-8-1-1, Ti-65K, Ti-6246, and IMI
 550. 